| Message ID | 1440093142-2413-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/md/md.c b/drivers/md/md.c index 8276c3b29ab4..b6eddaf97541 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5624,7 +5624,7 @@ static int get_bitmap_file(struct mddev * mddev, void __user * arg) char *ptr, *buf = NULL; int err = -ENOMEM; - file = kmalloc(sizeof(*file), GFP_NOIO); + file = kzalloc(sizeof(*file), GFP_NOIO); if (!file) goto out;
This is a note to let you know that I have just added a patch titled md: use kzalloc() when bitmap is disabled to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt17. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 0624b99bab2b572b28edc1fab3e2a6d8619ead3a Mon Sep 17 00:00:00 2001 From: Benjamin Randazzo <benjamin@randazzo.fr> Date: Sat, 25 Jul 2015 16:36:50 +0200 Subject: [PATCH] md: use kzalloc() when bitmap is disabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit b6878d9e03043695dbf3fa1caa6dfc09db225b16 upstream. In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a mdu_bitmap_file_t called "file". 5769 file = kmalloc(sizeof(*file), GFP_NOIO); 5770 if (!file) 5771 return -ENOMEM; This structure is copied to user space at the end of the function. 5786 if (err == 0 && 5787 copy_to_user(arg, file, sizeof(*file))) 5788 err = -EFAULT But if bitmap is disabled only the first byte of "file" is initialized with zero, so it's possible to read some bytes (up to 4095) of kernel space memory from user space. This is an information leak. 5775 /* bitmap disabled, zero the first byte and copy out */ 5776 if (!mddev->bitmap_info.file) 5777 file->pathname[0] = '\0'; Signed-off-by: Benjamin Randazzo <benjamin@randazzo.fr> Signed-off-by: NeilBrown <neilb@suse.com> Cc: Moritz Mühlenhoff <jmm@inutil.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)